(1) Field of the Invention
This invention relates to vehicle mirrors, and more particularly relates to an integrated, simplified system of vehicle mirrors, each having driver-operated adjustments of a single motor for remote, multi-axis directional alignment as well as for remote glare reduction without change of directional alignment.
(2) Description of Related Art
In numerous situations for drivers of vehicles, the reduction of glare due to reflections of incoming light from various sources is an important safety consideration. The internal rear-view mirror in most vehicles has a dual position feature for day/night setting. The glare is caused by light entering the vehicle from the rear, being reflected from one or more mirrors provided for viewing the rear scene, and then entering the driver's eyes. Such glare causes eye discomfort to the driver, makes it difficult for him to ascertain the overall driving scene, and thus creates a potentially hazardous driving environment. Most frequently, the undesirable glare results from headlights of other vehicles that are behind the viewing driver, particularly if the headlights of the following vehicle are set at "high-beam." On other occasions, light from the sun may cause the unwanted glare, particularly soon after sunrise or before sunset when the sun's rays are nearly horizontal.
The human eye readily adapts to bright lights during the daytime. The iris constricts and the light intensity is attenuated. In the daytime, the constricted iris allows only a tiny amount of light through the pupil, and minor changes of light intensity are not noticeable. At night the iris opens to allow the maximum amount of light into the eye through the enlarged pupil, and consequently, the eye is extremely sensitive to bright lights. Besides causing discomfort to the driver, another vehicle's high beam lights reflected in a rear-view mirror can cause momentary blindness as the eye adjusts to the bright light.
It is desirable that the rear view be presented to the driver continuously in at least two mirrors, and preferably in three mirrors. However, many drivers, in order to prevent unwanted glare from blinding them, rely solely upon the inside mirror (which has glare-reduction capability), and do not use the side mirrors (which do not have glare reduction capability), thereby handicapping visibility. In a typical situation, light beams from the headlights of vehicles behind the driver enter his eyes after reflections from a rear-view mirror mounted inside his vehicle near the top-center of the front windshield, from a left-side rear-view mirror mounted outside the vehicle, and frequently also from a right-side rear-view mirror. For directional alignment, the inside-mounted mirror is adjusted manually, and in modern vehicles has a day/night feature. For directional alignment of the externally mounted mirrors, most vehicles provide remotely operated adjustment mechanisms mounted inside the vehicle. Whether these mirrors are adjusted by remote control or by hand the driver will usually adjust the directional setting to obtain the best rear-view. The driver is forced to accept the glaring reflections from the left-side and right-side rear-view mirrors, since such mirrors do not have a day/night feature.
Currently no vehicle provides a left- (or right-) side rear-view mirror with a driver-controlled remote day/night reflectivity-adjustment feature. One luxury automobile offers a chemical glare-reduction feature similar to automatic sunglasses, but this is expensive and too slow-acting to eliminate momentary glare effectively during night driving. Further, it lacks the critically important manual override control for the driver. There is an important need to develop and provide convenient, safe, and economical mirrors for automobiles that reduce glare from all reflections. K. Jain, one of the named inventors, has provided such human factors in side mirrors having a remote high/low reflectivity adjustment, as well as a remote directional alignment mechanism, in U.S. Pat. No. 5,450,246, issued Sep. 12, 1995.
Mirrors that provide two different reflectivities are commonly used in road vehicles. Such mirrors operate on the same basic principle: they all use a wedge mirror to control the number and strength of reflections as a function of the angular position of the mirror. The reflectivity-adjustment feature for the inside-mounted rear-view mirror typically employs a wedge mirror, silvered on one side. The mirror is mounted so that its unsilvered side first receives the incident light beam. The high/low reflectivity adjustment consists of a mechanical lever that turns the wedge mirror by an appropriate angle (approximately 4.degree.) so that the incident beam travels either a short single-reflection path through the glass or a longer triple-reflection path through the glass to the driver's eyes. The turning angle is such that, in the single-reflection position, light traveling to the mirror enters the wedged glass plate, is reflected by the silvered rear surface, exits the glass plate, and reaches the driver's eyes; whereas in the triple-reflection position, the beam reflected from the rear-surface is reflected partially back from the front surface of the glass plate back to the rear surface, where it is again reflected, a second time, from the rear surface. The light, thrice reflected, exits the glass plate, and reaches the driver's eyes greatly diminished in intensity as a result of the much lower reflectivity of the unsilvered surface.
The functionality of the right-side exterior mirror is slightly different from the left-side exterior mirror. The left-side mirror is a flat mirror and provides unit magnification, as required by federal vehicle safety standards. In contrast, in a majority of automobiles, the right-side exterior rear-view mirror is a convex mirror. A convex mirror is provided to increase the angular field of view (albeit by less than 1:1 magnification, which makes following vehicles appear farther away than they are). Although increasing the view field of the driver, such a convex mirror, like the flat left-side mirror, reflects other drivers' headlights into the driver's eyes at night without attenuating the intensity of the beam, producing a hazardous glare situation. Thus, the problem of bright lights in the side view mirrors requires, as a solution, a day/night reflectivity control, for both left and right mirrors, which does not alter the view adjustment and is convenient, safe, and economical.
In the cited prior-art patent by one of the co-inventors, control of each outside mirror involves four motors--three for angular view adjustment and one for day/night reflectivity toggling. A second configuration of the prior art replaces the fourth motor with a solenoid. Also described is mirror control using three motors--in which the day/night motor (or solenoid) is eliminated, and the fixed shift for day/night change is accomplished by moving the three view angle adjustment motors suitably. Also previously described is a mirror system having only two motors--this is accomplished by having one of the above three motors replaced by a ball-and-socket pivot, and programming the two motors to provide the appropriate angular shifts in two orthogonal dimensions.
The above-referenced prior art U.S. Pat. No. 5,450,246, by K. Jain, describes a remote controlled, anti-glare vehicle mirror with excellent human factors, but does not provide an optimized minimal mechanical/electronic control system. The present invention discloses a complete remotely adjustable anti-glare vehicle mirror system including an integrated, user-friendly, minimal mechanical support and control system for each exterior mirror.